#----------------------------------------------------------------------------- # Copyright (c) 2012 - 2022, Anaconda, Inc., and Bokeh Contributors. # All rights reserved. # # The full license is in the file LICENSE.txt, distributed with this software. #----------------------------------------------------------------------------- ''' Provide the ``Document`` class, which is a container for Bokeh Models to be reflected to the client side BokehJS library. As a concrete example, consider a column layout with ``Slider`` and ``Select`` widgets, and a plot with some tools, an axis and grid, and a glyph renderer for circles. A simplified representation of this document might look like the figure below: .. figure:: /_images/document.svg :align: center :width: 65% A Bokeh Document is a collection of Bokeh Models (e.g. plots, tools, glyphs, etc.) that can be serialized as a single collection. ''' #----------------------------------------------------------------------------- # Boilerplate #----------------------------------------------------------------------------- from __future__ import annotations import logging # isort:skip log = logging.getLogger(__name__) #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- # Standard library imports import gc import weakref from json import loads from typing import TYPE_CHECKING, Any, Iterable # External imports from jinja2 import Template # Bokeh imports from ..core.enums import HoldPolicyType from ..core.has_props import is_DataModel from ..core.query import find, is_single_string_selector from ..core.serialization import Deserializer, Serialized, Serializer from ..core.templates import FILE from ..core.types import ID from ..core.validation import check_integrity, process_validation_issues from ..events import Event from ..model import Model from ..themes import Theme, built_in_themes, default as default_theme from ..util.serialization import make_id from ..util.strings import nice_join from ..util.version import __version__ from .callbacks import ( Callback, DocumentCallbackManager, EventCallback, MessageCallback, ) from .events import ( DocumentPatchedEvent, RootAddedEvent, RootRemovedEvent, TitleChangedEvent, ) from .json import DocJson, PatchJson from .models import DocumentModelManager from .modules import DocumentModuleManager if TYPE_CHECKING: from ..application.application import SessionContext, SessionDestroyedCallback from ..core.has_props import Setter from ..core.query import SelectorType from ..server.callbacks import ( NextTickCallback, PeriodicCallback, SessionCallback, TimeoutCallback, ) from .events import DocumentChangeCallback #----------------------------------------------------------------------------- # Globals and constants #----------------------------------------------------------------------------- DEFAULT_TITLE = "Bokeh Application" __all__ = ( 'Document', ) #----------------------------------------------------------------------------- # General API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- class Document: ''' The basic unit of serialization for Bokeh. Document instances collect Bokeh models (e.g. plots, layouts, widgets, etc.) so that they may be reflected into the BokehJS client runtime. Because models may refer to other models (e.g., a plot *has* a list of renderers), it is not generally useful or meaningful to convert individual models to JSON. Accordingly, the ``Document`` is thus the smallest unit of serialization for Bokeh. .. autoclasstoc:: ''' callbacks: DocumentCallbackManager models: DocumentModelManager modules: DocumentModuleManager _roots: list[Model] _theme: Theme _title: str _template: Template _session_context: weakref.ReferenceType[SessionContext] | None _template_variables: dict[str, Any] def __init__(self, *, theme: Theme = default_theme, title: str = DEFAULT_TITLE) -> None: self.callbacks = DocumentCallbackManager(self) self.models = DocumentModelManager(self) self.modules = DocumentModuleManager(self) self._roots = [] self._template = FILE self._template_variables = {} self._theme = theme self._title = title # avoid triggering title event self._session_context = None # Properties -------------------------------------------------------------- @property def roots(self) -> list[Model]: ''' A list of all the root models in this Document. ''' return list(self._roots) @property def session_callbacks(self) -> list[SessionCallback]: ''' A list of all the session callbacks for this document. ''' return self.callbacks.session_callbacks @property def session_destroyed_callbacks(self) -> set[SessionDestroyedCallback]: ''' A list of all the on_session_destroyed callbacks for this document. ''' return self.callbacks.session_destroyed_callbacks @session_destroyed_callbacks.setter def session_destroyed_callbacks(self, callbacks: set[SessionDestroyedCallback]) -> None: self.callbacks.session_destroyed_callbacks = callbacks @property def session_context(self) -> SessionContext | None: ''' The ``SessionContext`` for this document. ''' return self._session_context() if self._session_context is not None else None @property def template(self) -> Template: ''' A Jinja2 template to use for rendering this document. ''' return self._template @template.setter def template(self, template: Template) -> None: if not isinstance(template, (Template, str)): raise ValueError("document template must be Jinja2 template or a string") self._template = template @property def template_variables(self) -> dict[str, Any]: ''' A dictionary of template variables to pass when rendering ``self.template``. ''' return self._template_variables @property def theme(self) -> Theme: ''' The current ``Theme`` instance affecting models in this Document. Setting this to ``None`` sets the default theme. (i.e this property never returns ``None``.) Changing theme may trigger model change events on the models in the document if the theme modifies any model properties. ''' return self._theme @theme.setter def theme(self, theme: Theme | str | None) -> None: theme = default_theme if theme is None else theme if isinstance(theme, str): try: theme = built_in_themes[theme] except KeyError: raise ValueError(f"{theme} is not a built-in theme; available themes are {nice_join(built_in_themes)}") if not isinstance(theme, Theme): raise ValueError("Theme must be a string or an instance of the Theme class") if self._theme is theme: return self._theme = theme for model in self.models: self._theme.apply_to_model(model) @property def title(self) -> str: ''' A title for this document. This title will be set on standalone HTML documents, but not e.g. when ``autoload_server`` is used. ''' return self._title @title.setter def title(self, title: str) -> None: self.set_title(title) # Public methods ---------------------------------------------------------- def add_next_tick_callback(self, callback: Callback) -> NextTickCallback: ''' Add callback to be invoked once on the next tick of the event loop. Args: callback (callable) : A callback function to execute on the next tick. Returns: NextTickCallback : can be used with ``remove_next_tick_callback`` .. note:: Next tick callbacks only work within the context of a Bokeh server session. This function will no effect when Bokeh outputs to standalone HTML or Jupyter notebook cells. ''' from ..server.callbacks import NextTickCallback cb = NextTickCallback(callback=None, callback_id=make_id()) return self.callbacks.add_session_callback(cb, callback, one_shot=True) def add_periodic_callback(self, callback: Callback, period_milliseconds: int) -> PeriodicCallback: ''' Add a callback to be invoked on a session periodically. Args: callback (callable) : A callback function to execute periodically period_milliseconds (int) : Number of milliseconds between each callback execution. Returns: PeriodicCallback : can be used with ``remove_periodic_callback`` .. note:: Periodic callbacks only work within the context of a Bokeh server session. This function will no effect when Bokeh outputs to standalone HTML or Jupyter notebook cells. ''' from ..server.callbacks import PeriodicCallback cb = PeriodicCallback(callback=None, period=period_milliseconds, callback_id=make_id()) return self.callbacks.add_session_callback(cb, callback, one_shot=False) def add_root(self, model: Model, setter: Setter | None = None) -> None: ''' Add a model as a root of this Document. Any changes to this model (including to other models referred to by it) will trigger ``on_change`` callbacks registered on this document. Args: model (Model) : The model to add as a root of this document. setter (ClientSession or ServerSession or None, optional) : This is used to prevent "boomerang" updates to Bokeh apps. (default: None) In the context of a Bokeh server application, incoming updates to properties will be annotated with the session that is doing the updating. This value is propagated through any subsequent change notifications that the update triggers. The session can compare the event setter to itself, and suppress any updates that originate from itself. ''' if model in self._roots: return with self.models.freeze(): self._roots.append(model) self.callbacks.trigger_on_change(RootAddedEvent(self, model, setter)) def add_timeout_callback(self, callback: Callback, timeout_milliseconds: int) -> TimeoutCallback: ''' Add callback to be invoked once, after a specified timeout passes. Args: callback (callable) : A callback function to execute after timeout timeout_milliseconds (int) : Number of milliseconds before callback execution. Returns: TimeoutCallback : can be used with ``remove_timeout_callback`` .. note:: Timeout callbacks only work within the context of a Bokeh server session. This function will no effect when Bokeh outputs to standalone HTML or Jupyter notebook cells. ''' from ..server.callbacks import TimeoutCallback cb = TimeoutCallback(callback=None, timeout=timeout_milliseconds, callback_id=make_id()) return self.callbacks.add_session_callback(cb, callback, one_shot=True) def apply_json_patch(self, patch_json: PatchJson | Serialized[PatchJson], *, setter: Setter | None = None) -> None: ''' Apply a JSON patch object and process any resulting events. Args: patch (JSON-data) : The JSON-object containing the patch to apply. setter (ClientSession or ServerSession or None, optional) : This is used to prevent "boomerang" updates to Bokeh apps. (default: None) In the context of a Bokeh server application, incoming updates to properties will be annotated with the session that is doing the updating. This value is propagated through any subsequent change notifications that the update triggers. The session can compare the event setter to itself, and suppress any updates that originate from itself. Returns: None ''' deserializer = Deserializer(list(self.models), setter=setter) patch: PatchJson = deserializer.deserialize(patch_json) events = patch["events"] assert isinstance(events, list) # list[DocumentPatched] for event in events: # TODO: assert isinstance(event, DocumentPatchedEvent) DocumentPatchedEvent.handle_event(self, event, setter) def clear(self) -> None: ''' Remove all content from the document but do not reset title. Returns: None ''' with self.models.freeze(): while len(self._roots) > 0: r = next(iter(self._roots)) self.remove_root(r) def destroy(self, session: Any) -> None: self.remove_on_change(session) del self._roots del self._theme del self._template self._session_context = None self.callbacks.destroy() self.models.destroy() self.modules.destroy() # TODO (bev) ideally this should not be needed, but removing it will probably # require converting all Model back-references to Document to be weakrefs gc.collect() @classmethod def from_json(cls, doc_json: DocJson | Serialized[DocJson]) -> Document: ''' Load a document from JSON. doc_json (JSON-data) : A JSON-encoded document to create a new Document from. Returns: Document : ''' # TODO: deserialize model definitions if isinstance(doc_json, dict): doc_json["defs"] = [] deserializer = Deserializer() doc_struct = deserializer.deserialize(doc_json) roots = doc_struct["roots"] title = doc_struct["title"] doc = Document() for root in roots: doc.add_root(root) doc.title = title return doc @classmethod def from_json_string(cls, json: str) -> Document: ''' Load a document from JSON. json (str) : A string with a JSON-encoded document to create a new Document from. Returns: Document : ''' json_parsed = loads(json) return cls.from_json(json_parsed) def get_model_by_id(self, model_id: ID) -> Model | None: ''' Find the model for the given ID in this document, or ``None`` if it is not found. Args: model_id (str) : The ID of the model to search for Returns: Model or None ''' return self.models.get_by_id(model_id) def get_model_by_name(self, name: str) -> Model | None: ''' Find the model for the given name in this document, or ``None`` if it is not found. Args: name (str) : The name of the model to search for Returns: Model or None ''' return self.models.get_one_by_name(name) def hold(self, policy: HoldPolicyType = "combine") -> None: ''' Activate a document hold. While a hold is active, no model changes will be applied, or trigger callbacks. Once ``unhold`` is called, the events collected during the hold will be applied according to the hold policy. Args: hold ('combine' or 'collect', optional) Whether events collected during a hold should attempt to be combined (default: 'combine') When set to ``'collect'`` all events will be collected and replayed in order as-is when ``unhold`` is called. When set to ``'combine'`` Bokeh will attempt to combine compatible events together. Typically, different events that change the same property on the same mode can be combined. For example, if the following sequence occurs: .. code-block:: python doc.hold('combine') slider.value = 10 slider.value = 11 slider.value = 12 Then only *one* callback, for the last ``slider.value = 12`` will be triggered. Returns: None .. note:: ``hold`` only applies to document change events, i.e. setting properties on models. It does not apply to events such as ``ButtonClick``, etc. ''' self.callbacks.hold(policy) def on_change(self, *callbacks: DocumentChangeCallback) -> None: ''' Provide callbacks to invoke if the document or any Model reachable from its roots changes. ''' self.callbacks.on_change(*callbacks) def on_change_dispatch_to(self, receiver: Any) -> None: ''' ''' self.callbacks.on_change_dispatch_to(receiver) def on_event(self, event: str | type[Event], *callbacks: EventCallback) -> None: ''' Provide callbacks to invoke if a bokeh event is received. ''' self.callbacks.on_event(event, *callbacks) def on_message(self, msg_type: str, *callbacks: MessageCallback) -> None: ''' ''' self.callbacks.on_message(msg_type, *callbacks) def on_session_destroyed(self, *callbacks: SessionDestroyedCallback) -> None: ''' Provide callbacks to invoke when the session serving the Document is destroyed ''' self.callbacks.on_session_destroyed(*callbacks) def remove_next_tick_callback(self, callback_obj: NextTickCallback) -> None: ''' Remove a callback added earlier with ``add_next_tick_callback``. Args: callback_obj : a value returned from ``add_next_tick_callback`` Returns: None Raises: ValueError, if the callback was never added or has already been run or removed ''' self.callbacks.remove_session_callback(callback_obj) def remove_on_change(self, *callbacks: Any) -> None: ''' Remove a callback added earlier with ``on_change``. Raises: KeyError, if the callback was never added ''' self.callbacks.remove_on_change(*callbacks) def remove_on_message(self, msg_type: str, callback: MessageCallback) -> None: ''' ''' self.callbacks.remove_on_message(msg_type, callback) def remove_periodic_callback(self, callback_obj: PeriodicCallback) -> None: ''' Remove a callback added earlier with ``add_periodic_callback`` Args: callback_obj : a value returned from ``add_periodic_callback`` Returns: None Raises: ValueError, if the callback was never added or has already been removed ''' self.callbacks.remove_session_callback(callback_obj) def remove_root(self, model: Model, setter: Setter | None = None) -> None: ''' Remove a model as root model from this Document. Changes to this model may still trigger ``on_change`` callbacks on this document, if the model is still referred to by other root models. Args: model (Model) : The model to add as a root of this document. setter (ClientSession or ServerSession or None, optional) : This is used to prevent "boomerang" updates to Bokeh apps. (default: None) In the context of a Bokeh server application, incoming updates to properties will be annotated with the session that is doing the updating. This value is propagated through any subsequent change notifications that the update triggers. The session can compare the event setter to itself, and suppress any updates that originate from itself. ''' if model not in self._roots: return with self.models.freeze(): self._roots.remove(model) self.callbacks.trigger_on_change(RootRemovedEvent(self, model, setter)) def remove_timeout_callback(self, callback_obj: TimeoutCallback) -> None: ''' Remove a callback added earlier with ``add_timeout_callback``. Args: callback_obj : a value returned from ``add_timeout_callback`` Returns: None Raises: ValueError, if the callback was never added or has already been run or removed ''' self.callbacks.remove_session_callback(callback_obj) def replace_with_json(self, json: DocJson) -> None: ''' Overwrite everything in this document with the JSON-encoded document. json (JSON-data) : A JSON-encoded document to overwrite this one. Returns: None ''' replacement = self.from_json(json) replacement._destructively_move(self) def select(self, selector: SelectorType) -> Iterable[Model]: ''' Query this document for objects that match the given selector. Args: selector (JSON-like query dictionary) : you can query by type or by name, e.g. ``{"type": HoverTool}``, ``{"name": "mycircle"}`` Returns: seq[Model] ''' if is_single_string_selector(selector, 'name'): # special-case optimization for by-name query return self.models.get_all_by_name(selector['name']) return find(self.models, selector) def select_one(self, selector: SelectorType) -> Model | None: ''' Query this document for objects that match the given selector. Raises an error if more than one object is found. Returns single matching object, or None if nothing is found Args: selector (JSON-like query dictionary) : you can query by type or by name, e.g. ``{"type": HoverTool}``, ``{"name": "mycircle"}`` Returns: Model or None ''' result = list(self.select(selector)) if len(result) > 1: raise ValueError(f"Found more than one model matching {selector}: {result!r}") if len(result) == 0: return None return result[0] def set_select(self, selector: SelectorType | type[Model], updates: dict[str, Any]) -> None: ''' Update objects that match a given selector with the specified attribute/value updates. Args: selector (JSON-like query dictionary) : you can query by type or by name,i e.g. ``{"type": HoverTool}``, ``{"name": "mycircle"}`` updates (dict) : Returns: None ''' if isinstance(selector, type) and issubclass(selector, Model): selector = dict(type=selector) for obj in self.select(selector): for key, val in updates.items(): setattr(obj, key, val) def set_title(self, title: str, setter: Setter | None = None) -> None: ''' ''' if title is None: raise ValueError("Document title may not be None") if self._title != title: self._title = title self.callbacks.trigger_on_change(TitleChangedEvent(self, title, setter)) def to_json(self, *, deferred: bool = True) -> DocJson: ''' Convert this document to a JSON-serializble object. Return: DocJson ''' data_models = [ model for model in Model.model_class_reverse_map.values() if is_DataModel(model) ] serializer = Serializer(deferred=deferred) defs = serializer.encode(data_models) roots = serializer.encode(self._roots) doc_json = DocJson( version=__version__, title=self.title, defs=defs, roots=roots, ) self.models.flush() return doc_json def unhold(self) -> None: ''' Turn off any active document hold and apply any collected events. Returns: None ''' self.callbacks.unhold() def validate(self) -> None: ''' Perform integrity checks on the modes in this document. Returns: None ''' for r in self.roots: refs = r.references() issues = check_integrity(refs) process_validation_issues(issues) # Private methods --------------------------------------------------------- def _destructively_move(self, dest_doc: Document) -> None: ''' Move all data in this doc to the dest_doc, leaving this doc empty. Args: dest_doc (Document) : The Bokeh document to populate with data from this one Returns: None ''' if dest_doc is self: raise RuntimeError("Attempted to overwrite a document with itself") dest_doc.clear() # we have to remove ALL roots before adding any # to the new doc or else models referenced from multiple # roots could be in both docs at once, which isn't allowed. roots: list[Model] = [] with self.models.freeze(): while self.roots: r = next(iter(self.roots)) self.remove_root(r) roots.append(r) for r in roots: if r.document is not None: raise RuntimeError("Somehow we didn't detach %r" % (r)) if len(self.models) != 0: raise RuntimeError(f"_all_models still had stuff in it: {self.models!r}") for r in roots: dest_doc.add_root(r) dest_doc.title = self.title #----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Code #-----------------------------------------------------------------------------